from shutil import copyfileobj

from werkzeug.datastructures import FileStorage

try:
    from xlrd import xlsx
except ImportError:
    pass
else:
    from lxml import etree
    # xlrd.xlsx supports defusedxml, defusedxml's etree interface is broken
    # (missing ElementTree and thus ElementTree.iter) which causes a fallback to
    # Element.getiterator(), triggering a warning before 3.9 and an error from 3.9.
    #
    # We have defusedxml installed because zeep has a hard dep on defused and
    # doesn't want to drop it (mvantellingen/python-zeep#1014).
    #
    # Ignore the check and set the relevant flags directly using lxml as we have a
    # hard dependency on it.
    xlsx.ET = etree
    xlsx.ET_has_iterparse = True
    xlsx.Element_has_iter = True

FileStorage.save = lambda self, dst, buffer_size=1<<20: copyfileobj(self.stream, dst, buffer_size)